The effect of the combined use of gammaoctalactone and chlortetracycline in the broiler diet: live weight, feed efficiency and the microbiome of the caecum

Abstract

Relevance, materials and methods. The experimental scheme included the control group — the main diet (MD); group I (positive control) — MD + chlortetracycline (20%) 0.63 g per 1 kg of body weight for 20 days; group II — MD + gamma-octalactone at a dosage of 0.1 ml/kg of b.w./day; III group — MD + gammaoctalactone + chlortetracycline (20%).Results. In the course of research, the advantage of the live weight of experimental broilers over the control was established. The broilers that received gamma-octolactone + chlortetracycline with the main dietwere distinguished by the greatest live weight (16.5% more than in the control) . A similar situation was observed in terms of live weight gains. Broilers of the experimental groups ate more feed (by 3.23–8.47%), against the background of low feed consumption per 1 kg of live weight (by 6.38–10.6%) compared to the control. Broilers from group III had a higher content of erythrocytes (by 12.6–30.7%) and the weight of the spleen. The microbial profile of group III broilers (a combination of gamma-octalactone and chlortetracycline) was represented by microorganisms belonging to 4 phylum. The dominant phylum was Firmicutes (81.3%). Comparison with the control showed that the combination of substances reduced the number of bacteria of this phylum by 4.46%, against the background of an increase in the number of representatives of the Bacteroidetes phylum by 9.32% relative to the control. There was an increase in representatives of the genera Alistipes, Lactobacillus and unclassified genera of the family Clostridiales, while the number of representatives of unclassified genera of the family Ruminococcaceae decreased.